Research On The Vibration Reduction Characteristics Of CFRP Motor Base

As the part directly connected with the system,electric motor base plays the role of supporting iron core,winding,end cover and other components in the whole motor structure and it is also the main component at the motor's vibration transmission path.Traditional motor base is usually made of metal material such as cast iron,aluminum alloy with large proportion and small damping ratio,which results in the problem of noise and vibration of the whole system while the electric motor is under centrifugal load or the three-phase voltage is instability.Carbon Fiber Reinforced Plastic(CFRP)is a kind of fiber reinforced composites with resin matrix.Compared with traditional metal materials,CFRP has many advantages,such as high specific modulus and strength,excellent damping performance and good designability.Its damping is tens to hundreds higher than that of metal materials,so it is often used to manufact structural parts with vibration reduction requirements.By introducing CFRP into the motor base,starting from improving the damping energy dissipation characteristics of the motor base and adopting the means of damping vibration reduction,not only the vibration reduction design method of the motor system is expanded,but also the strength and damping advantages of the composite material can be brought into full play to meet the actual vibration reduction requirements,so it is of great significance.Therefore this paper mainly focuses on the studies about vibration characteristics of CFRP motor base.Based on the analysis of the modal frequency and damping ratio of the CFRP motor base,the vibration characteristics and vibration reduction performance of the CFRP motor base are analyzed and studied by means of the combination of finite element simulation and experimental verification.The main contents of this paper are as follows:Firstly,on the basis of standard JW6314 three-phase asynchronous motor,the structure design of CFRP motor base is carried out.The modal vibration characteristics are simulated and analyzed in Abaqus finite element software,and the first four-order damping ratio of CFRP motor base is calculated based on the damping prediction model of strain energy.The natural frequency and damping ratio of CFRP motor base are studied in detail with different pavement angles.The harmonic excitation responses of both CFRP and aluminium alloy motor bases are studied.All simulation results show that in the first four modes,the CFRP motor base has smaller resonance peak value and larger natural frequency than the aluminium alloy base.Secondly,on the basis of considering the forming process and difficulty of composite materials,the CFRP motor base is manufacted with T700/YPH-42T prepreg,and the vibration modal experiment is carried out.The experimental results show that the error between measured and simulated natural frequencies of CFRP motor base is less than 10%.The second-order and third-order damping ratios are0.87%and 0.69%respectively,which are 11.49%and 15.49%different from the simulation results.This proves the correctness of the model for predicting modal strain energy damping.Finally,the pressing and assembling of the new electric motor are completed by DNS100 universal testing machine,and the vibration acceleration amplitude at the base and cylinder shell is used as the evaluation index to test and compare the vibration of CFRP motor base and aluminum alloy motor base.The results show that when the motor speed is between 1000r/min and 1500r/min,the vibration acceleration amplitude of each measuring point of CFRP motor base is smaller than that of aluminum alloy motor base.With the increase of motor speed,the acceleration on the CFRP motor base fluctuates around 20 mm/s~2,while the acceleration on the shell decreases gradually.It is proved that the CFRP motor base has better vibration reduction effect than the aluminum alloy base of aluminum alloy motor base.